Motorola MVME2400 用户手册
3-10
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Functional Description
3
PPC Bus Latency
The following tables list the latency of PPC originated transactions and the
bandwidth of originated transactions for five different clock ratios: 5:2,
3:2, 3:1, 2:1, and 1:1. The MVME2400 uses a 3:1 clock ratio:
bandwidth of originated transactions for five different clock ratios: 5:2,
3:2, 3:1, 2:1, and 1:1. The MVME2400 uses a 3:1 clock ratio:
Table 3-5. PPC60x Originated Latency Matrix
Transaction
32-bit PCI
64-bit PCI
Clock
Ratio
Beat
1
Beat
2
Beat
3
Beat
4
Total
Beat
1
Beat
2
Beat
3
Beat
4
Total
Burst Read
40
1
1
1
43
29
1
1
1
32
5:2
Burst Write
5
1
1
1
8
5
1
1
1
8
Single Read
22
-
-
-
22
-
-
-
-
-
Single Write
5
-
-
-
5
-
-
-
-
-
Burst Read
26
1
1
1
29
20
1
1
1
23
3:2
Burst Write
5
1
1
1
8
5
1
1
1
8
Single Read
16
-
-
-
16
-
-
-
-
-
Single Write
5
-
-
-
5
-
-
-
-
-
Burst Read
45
1
1
1
48
33
1
1
1
36
3:1
Burst Write
5
1
1
1
8
5
1
1
1
8
Single Read
24
-
-
-
24
-
-
-
-
-
Single Write
5
-
-
-
5
-
-
-
-
-
Burst Read
33
1
1
1
36
25
1
1
1
28
2:1
Burst Write
5
1
1
1
8
5
1
1
1
8
Single Read
19
-
-
-
19
-
-
-
-
-
Single Write
5
-
-
-
5
-
-
-
-
-
Burst Read
20
1
1
1
23
16
1
1
1
19
1:1
Burst Write
5
1
1
1
8
5
1
1
1
8
Single Read
13
-
-
-
13
-
-
-
-
-
Single Write
5
-
-
-
5
-
-
-
-
-